This invention relates to a time recorder to perform the automatic positioning control of print lines independently for each individual time card.
As well known, in many ordinary time recorders, a print line-positioning mechanism for determining a particular line of time card inserted, on which the time of day will be printed, is driven every time when a certain predetermined time (this is also called "line switching time") is reached, and the daily print location of the print line of the time card is updated by one line everyday.
That is, the time of arrival at and the time of departure from the place of work and so forth are all printed on the same line of a time card inserted in a particular day. This method of control for the print line is very suited to those places of business where each and every worker will come only once a day to and depart only once a day from the place of work.
However, the conventional time recorders stated above are not able to correctly record the work data of each employee on the time card if, in a certain place of work, the pattern of work of each worker is different from those of others; for instance, some person has to come to his place of work more than twice a day or some person has to stay in his place of work for more than 2 days between his arrival to and departure from his place of work.
For the place of work where the job contents of each worker cannot be uniformly processed on the daily basis, certain types of time recorders described below have been conventionally available. That is, a certain type of time recorder has a marker for showing the print complete mark (with a punched hole or printed character) to indicate the last line printed on time card as the printing of the times of arrival at and departure from the place of work progresses, and also has a mark sensor for detecting said print complete mark of time card inserted. And this time recorder will perform the print positioning for the time card, basing upon the signal detected by the mark sensor.
Some of the shortcomings of this kind of time recorders are that their costs are high since said marker and mark sensor are used only for the positioning control of the print line number and that erroneous operation easily occurs because of the stain or scratch on card if said marker and mark sensor have been simplified to reduce the cost. Naturally, their reliability can be greatly improved by using a control method adopting a relatively sophisticated error correcting code, but this will result in a complicated control system containing said marker and mark sensor and a great increase in cost.